Cell biology Flashcards
Qualities of eukaryotic cells?
- Multicellular
- Contain membrane bound organelles
- DNA is membrane bound
So basically animal cells
Qualities of prokaryotic cells?
- Single celled
- Does not contain any membrane bound organelles
- DNA is free in the nucleus
Basically bacteria etc
What organelles do plant cells and animal cells both contain?
A nucleus
Cell membrane
Cytoplasm
Mitrochondrion
What organelles are only found in plant cells?
Cell wall
Vacuole
Chloropasts
What do all the organelles in cells do? (7)
Nucleus - Contain DNA and controls what happens in the cell
Cell membrane - Controls what goes in and out of the cell
Cytoplsm - Where most chemical reactions happen
Mitrochondria - Site of respiration
Cell wall - Holds the structure of the cell
Vacuole - To store substances
Chloroplasts - Needed for photosynthesis
What is the meaning of magnification?
How much bigger an object is compared to its real life sample
What is resolution?
How far apart two objects have to be for them to be seen as seperate
Light microscope qualities?
- Limited by the wavelength of light
- Two lenses, Objective and Eyepiece
- The total magnification of a light microscope can be worked out by mulitplying these two lenses together
What is the maximum resolution of a light microscope?
What is the maximum magnification of a light microscope?
The max resolution is 200nm,
The max magnification is x 2000
Qualities of an electron micrscope?
- They use a beam of electrons rather than light
- There are two types; Scanning and Transmission
What is the max resolution of an electron microscope?
What is the max magnification of an electron microscope?
The max resolution is 0.5nm,
The max magnification is x100,000,000
What is a scanning electron microscope like?
- Black and white
- 3D images of the specimen’s surface
What is a transission electron microscope like?
- Black and white
- 2D image of specimen
What are specialised cells?
Cells can become specialised in order to perform a specific task. They become specialised through the process of cell differentiation.
What happens to cells when they become specialised?
When a cell becomes speiclised it loses its ability to divide and make copies of itself.
What is a stem cell?
An undifferentiated cell which still has the ability to divide.
Adult stem cells?
Animal stem cells can be found in fully developed areas such as bone marrow, teeth, blood vessels and the liver.
These stem cells are multipotent and can only become a few different types of cells
Embryonic stem cells?
These are also animal stem cells. These stem cells are taken from the embryo very early in development.
Embryonic stem cells are pluripotent, they can become any type of cell in the body
Plant stem cells?
These are called meristem cells. They are pluripotent throughout the life of the plant, allowing itself to grow and repair.
What is cell division?
Cell division is needed for organisms to grow, repair and replace cells.
Only stem cells can divide - they are undifferentiated.
What are chromosomes?
Chromosomes are found in the nucleus, they are made of DNA which is tightly wound around proteins.
The DNA has specific regions called genes, each gene has the code to making a specific protein. Proteins control all functions of the body.
In the cell cycle, what is the first phase - what happens?
Interphase
Organelles increase in number
DNA duplicates
In the cell cycle, what is the second phase - what happens?
Mitosis
The chromosomes line up in the centre of the cell
They are seperated to either pole of the cell
The nucleus then splits
In the cell cycle, what is the third phase - what happens?
Cytokinesis
The cytoplasm and membrane split
Two new cells are formed
Two cells are genetically identical to parent cell
